The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A262427 Decimal expansion of the complete elliptic integral of the first kind at sqrt(2*sqrt(2) - 2). 6
2, 3, 2, 7, 1, 8, 5, 1, 4, 2, 4, 3, 6, 5, 3, 8, 7, 5, 0, 6, 0, 5, 0, 3, 6, 2, 8, 5, 6, 1, 8, 3, 5, 7, 0, 7, 7, 5, 1, 5, 1, 8, 1, 7, 5, 8, 2, 3, 2, 5, 4, 1, 1, 7, 4, 7, 9, 3, 2, 0, 8, 1, 9, 9, 4, 4, 6, 1, 1, 8, 8, 2, 5, 7, 3, 1, 3, 6, 0, 4, 9, 5, 7, 8, 2, 2, 5, 9, 0, 0, 7, 0, 1, 1, 0, 6, 6, 1, 0, 5, 6, 2, 3, 7, 1 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
M. L. Glasser and V. E. Wood, A closed form evaluation of the elliptic integral, Math. Comp. 25 (1971), 535-536.
FORMULA
Equals Pi^(3/2)*sqrt(4 + 2*sqrt(2))/(4*Gamma(5/8)*Gamma(7/8)).
Also equals sqrt(2)*K(sqrt(2) - 1).
Also equals 2*Integral_{x=0..1} 1/sqrt(1-x^8) dx. - Christian N. Hofmann, Jun 24 2023
Also equals Pi^(3/2)*cos(Pi/4)*cos(Pi/8)/(Gamma(5/8)*Gamma(7/8)). - Christian N. Hofmann, Aug 20 2023
Equals Gamma(1/8)^2 / (2^(11/4) * Gamma(1/4)). - Vaclav Kotesovec, Apr 15 2024
EXAMPLE
2.3271851424365387506050362856183570775151817582325411747932...
MAPLE
evalf(sqrt(2)*EllipticK(sqrt(2)-1), 120); # Vaclav Kotesovec, Sep 22 2015
evalf(int(2/sqrt(1-x^8), x=0..1), 120); # Christian N. Hofmann, Jun 28 2023
MATHEMATICA
K[x_] := EllipticK[x^2/(x^2 - 1)]/Sqrt[1 - x^2]; RealDigits[ K[Sqrt[2 Sqrt[2] - 2]], 10, 105][[1]]
PROG
(PARI) ellk(k)=intnum(t=0, 1, 1/sqrt((1-t^2)*(1-(k*t)^2)))
sqrt(2)*ellk(sqrt(2)-1) \\ Charles R Greathouse IV, Apr 18 2016
(Magma) SetDefaultRealField(RealField(100)); R:= RealField(); Pi(R)^(3/2)*Sqrt(4 + 2*Sqrt(2))/(4*Gamma(5/8)*Gamma(7/8)); // G. C. Greubel, Oct 07 2018
CROSSREFS
Cf. A130786.
Sequence in context: A354796 A104565 A144456 * A333986 A349664 A266258
KEYWORD
cons,nonn
AUTHOR
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 19 00:35 EDT 2024. Contains 372666 sequences. (Running on oeis4.)